This proposal explores the relation between learning natural language terms such as "dog," "cup," and "ball," and acquiring kind concepts which underlie these lexical items. Kind concepts are among the most basic categorical distinctions adults make and words for object categories are among children's first words, thus through this project we address the fundamental question of the relation between language and thought at the onset of language acquisition. Specifically the proposed study explores the possibility that learning words such as "cup" may play a role in helping infants acquire concepts such as cup. The experiments use a standard infant habituation-dishabituation paradigm and measure infants' looking times as the basis of inferring the infants' representations. In an object individuation task in which infants are asked to infer two distinct objects after being shown one object at a time, e.g., a ball emerges from behind a screen then returns, followed by a cup emerging from behind the same screen then returning. When the screen is removed after familiarization, the infants are then shown the expected outcome of a cup and a ball or the unexpected outcome of only the cup or only the ball. For some conditions, labels were provided during the experiment to see if they would allow the infant to succeed at this task earlier than previously thought. The long term goal of the project is to systematically address the question whether acquiring count nouns can facilitate categorization in human infants and whether language is necessary for acquiring kind concepts. The proposed study will provide very valuable preliminary data for a full grant proposal to be submitted to NIH in the near future.